An optical communications system or network may comprise one or more links, where a given link connects a transmitter to a receiver by one or more optical fibers. Each link may comprise one or more spans, where a given span comprises a length of fiber and one or more optical amplifiers used to compensate for the attenuation loss in that span.
As a result of chromatic dispersion (CD), an input signal may broaden as it travels down a length of fiber. The net CD of a link may be compensated for using pre-compensation at the transmitter, or post-compensation at the receiver, or some combination thereof. Different fiber types may have different CD characteristics.